Lamp socket



S. l. SPENDER Nov. 9,1937.

LAMP SOCKET Filed OCT.. l5, 1935 lNVE.

ATTORNEY S Patented Nov. 9, 1.937

UNITED STATES PATENT OFFICE LAMP SOCKET Application October 15, 1935, Serial No. 45,032

Claims.

This invention relates to lamp sockets.

The ordinary lamp socket comprises a shell which contains the switch mechanism and a cap. For purposes of assembly, repair and the like,

5 the cap can be readily detached and replaced. It is necessary to have some means for prevent-V ing relative rotation of the shell and cap and for detachably looking the cap against removal. In previously known constructions the shell has one or more downwardly facing shoulders, usually formed by punching out the metal. side of the cap are one or more lugs or shoulders which snap over the shell shoulders when the cap is assembled, thus locking the cap against endwise movement and hence against removal. To prevent relative rotation the shells have had one or more laterally facing shoulders engaged by lugs or the like on the cap.

In order to enable the twosocket parts to be assembled without regard to relative angular position, it has been customary to duplicate the locking elements of the cap in a row around the same.

In one type of cap previously known, a row of locking lugs is formed around the skirt of the cap by punching in the metal. This defaces and perforates the cap skirt and makes a rather unsightly socket which is objectionable commer cially. To obtain the desired locking without defacing the skirt, it has been proposed to make a two-piece cap skirt, the inner piece having the requisite locking elements. This type of construction, however, has proved disadvantageous because it is relatively complicated and expensive to manufacture.

A further objection to lamp sockets as heretofore constructed is that the cap, at least in many instances, is further defaced, from a commercial point of view, by struck-in nibs above the skirt for holding in insulation.

It is an object of the present invention to provide a lamp socket of the general type referred to, in which the above mentioned objections are avoided. More particularly, it is an object of the invention to provide a lamp socket in which the cap has an imperforate and undefaced outer surface and at the same time has a one-piece skirt.

It is a further object of the invention to provide a lamp socket in which the cap and shell are effectively locked against separation and in which the use of additional means for preventing relative rotation is avoided.

With these general objects and others in view the invention consists of the features, combinations, details of construction and arrangements On the inof parts that will rst be described in connection with the accompanying drawing and then more particularly pointed out.

In the drawing,-

Figure l'is a view in vertical section of a lamp socket constructed in accordance with the invention;

Figure 2 is a bottom plan View of the cap;

Figure 3 is a top plan view'of the shell, and

Figure 4 is a sectional view (enlarged) taken on the line 4-4 of Figure l.

Referring to the drawing, the lamp socket here illustrated as an example comprises a shell l5 and a cap I6. The upper part of the shell is fluted, as at Il, the several flutes constituting a plurality of equally spaced recesses. The lower part of the shell has the usual screw thread I8 for reception of a light bulb or the like. The topredge of the shell is out away, as indicated at I9, Vto form the usual notch for a switch key (not shown).

There is provided locking means for cooperation with the cap to prevent separation of cap and shell. As here shown as an example, downwardly facing locking shoulders are formed by nibs 20 struck in from the metal of the shell and located in the ilutes or recesses Il. As ap* pears more clearly in Figure l, the sheared edges of these nibs constitute the locking shoulders. In the present embodiment two of these looking elements are located, respectively, in the two utes adjacent the key notch and two more at points generally diametrically opposite.

The invention in its entirety includes a cap having a one-piece skirt with an imperforate and undefaced outer surface and a substantially continuous and unbroken bottom edge. Inside this skirt, the cap has a plurality of locking elements and in structures embodying the invention to what is now considered the best advantage, the locking elements are in the form of equally spaced lugs integral with the cap skirt. Although capable of various constructions, in that here shown as an example, the cap I6 has a body portion or dome 2|, a thimble 22 secured thereto, and a depending skirt or band 23. The skirt 23 is imperforate and its outer surface is undefaced and its bottom edge is unbroken. Extending inwardly from the bottom edge of this skirt are a plurality of arcuate lugs or scallops 24 lying in a plane substantially at right angles to the axis of the cap. These scallops are spaced and numbered to accord with the flutes of the socket shell and are dimensione'd to t within the latter.

The lugs or scallops 24 may be formed in any suitable manner, for example, by making the cap skirt blank over-length, scalloping the bottom edge of the blank and bending the scallops in at right angles.

When the cap is assembled on the shell the scallops 24 or the locking nibs 2B, or both, yield sufficiently to permit the lugs to pass the nibs and snap under the shoulders thereof. So assembled, the lugs 24 engage the downwardly facing shoulders of locking nibs 2i) and releasably lock the cap against axial movement and hence against removal. At the same time, the interfit of the scallops 24 with the utes Il prevents relative rotation of cap and shell without the necessity of additional locking elements. It will be seen that the several scallops 24 are duplicates and that with a number of scallops equal to the number of flutes the cap and shell may be assembled without regard to the relative angular position thereof.

To disassemble the parts, it is only necessary to exert sumcient thumb pressure on the shell adjacent the key notch I9. At this point, because of the notch, the shellyields more readily and the yield moves the nibs 2li sufficiently out oi the Way to permit the corresponding lugs 24 to pass. The cap may then be removed by tilting the same at that point and then elevating it at the opposite point.

With the construction described, the outer sur face of slL'rt of the cap is not defaced and the bottom edge is unbroken, thus presenting the neat appearance demanded by the trade. At the same time, the skirt is in one piece, thus avoiding manufacturing complications.

The invention in its entirety includes an annular bead for holding in insulation. As here shown as an example, at the point where the dome 2| of the cap meets skirt 23, there is an inwardly pressed annular bead 25 which forms a shoulder for holding in the fibre insulation (not shown). Being annular, the bead functions more effectively than do a number of widely spaced nibs such as were formerly used. Moreover, the bead, being annular and being located at the junction of the dome and skirt, merges into the latter and is so inconspicuous as to be practically unnoticeable. In appearance, it is decorative rather than defacing, thus removing the objections to the struck-in nibs of previous constructions.

What is claimed is:

1. In 'a lamp socket, and in combination, a shell having its upper portion luted, a plurality of downwardly facing locking shoulders on said shell and located in the utes thereof, a cap having a top portion and a depending skirt for taking over the upper end of the shell, and a plurality of scallop-shaped lugs extending inwardly from the bottom edge of the cap skirt for cooperating with said shoulders to prevent axial separation of cap and shell and for tting in said flutes to prevent relative rotation thereof.

2. In a lamp socket, and in combination, a shell having its upper portion fluted, a plurality of downwardly facing locking shoulders on said shell and located in the flutes thereof, a cap having a top portion and a depending skirt for taking over the upper end of the shell, and a plurality of scallop-shaped lugs extending inwardly from the bottom edge of the skirt and integral therewith, said lugs cooperating with said shoulders and flutes to prevent axial separation and relative rotation of cap and shell.

3. A metal cap for a lamp socket comprising a top portion anda depending skirt, and a plurality of scallop-shaped lugs extending inwardly from the bottom edge of said skirt.

4. A metal cap for a lamp socket comprising a top portion and a depending skirt, and a plurality of equally spaced and scallop-shaped integral lugs extending inwardly from the bottom edge of the skirt. l

5. A metal cap for a lamp socket comprising a top portion and a depending skirt, and a plurality of scallop-shaped lugs integral with said skirt and extending inwardly from the bottom edge thereof and at an angle thereto.

SYDNEY I. SPENDER. 

